Hmm...
Strange statement.
So, you may remove Close button from application, because isn't something that many people have asked for. Users can close application using CMD+Q shortcut, or just turn off their Mac...

There's a difference between removing standard functionality, and adding a feature. While many apps have search features, it isn't something that comes "for free" with an app; each app that chooses to add it has to implement it in a way that makes sense for that app.

Yes, you are right.
But searching - is standart functionality for ANY apps with lists I met before.
Users use Spotlight on macOS to start applications even they have only 20-30 programs. Because it's conveniently.
Anyway, thanks for dialog.